The process of a liquid changing to a gaseous state

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How liquid boils in a cylindrical piston at boiling point? [closed]

in a cylindrical piston which contains liquid with no space between the piston and liquid the liquid will not evaporate as there is no space. then how does the liquid boils when the temperature is ...
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5answers
77 views

Temperature to make oceans evaporate [closed]

The Boiling point of the water is 100 C after that water evaporates. If we are to heat the water of all the oceans combined, what should the temperature be set at, so that all the water gets ...
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1answer
57 views

Calculating rate of vaporization of water

Let there be a cylindrical vessel with diameter D that only has liquid water and water vapor as the picture below shows (The water vapor is the grey portion and the liquid water is the blue portion). ...
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0answers
34 views

Smell the Coffee [closed]

Do non-water particles of coffee evaporate or leave the surface of hot coffee over time? Are they some sort of carbon-based molecules? Are they carried into the air by the evaporating water molecules? ...
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0answers
19 views

Difference between smoke and vapor in sealed space

I got a questions. I've got a sphere that has only one hole on the bottom. I tried it out and inside of the sphere, fire is extinguished instantly (it does not even enter the sphere through the hole). ...
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1answer
48 views

Boiling is not well described? [duplicate]

It is said that boiling occurs only when the vapour pressure becomes equal to the pressure surrounding the vapour (say atmospheric pressure). Why does it take place only satisfying these conditions ...
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0answers
32 views

Why is it valid to assume that the liquid-vapour interface is always saturated during evaporation?

For steady state evaporation, I read from two textbooks which simply states that the partial pressure of vapour of interest (say water) at the liquid-vapour interface is equal to the saturation ...
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5answers
121 views

What keeps water molecules in air from falling down?

I was thinking about evaporative cooling, how the particles in water with the most velocity fly out of the water, leaving it colder. But then I thought, how come these water molecules stay in the air ...
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3answers
232 views

On boiling, does 1 kg of water give rise to 1 kg of steam?

I understand that by conservation of mass, it implies that 1 kg of water will give rise to 1 kg of steam. But when I consider the fact that there is phase change which is an abrupt and discontinuous ...
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1answer
575 views

Why can I see my breath after I pop my ears?

I have this weird but reproducible thing that I can see my breath for less than a second even in hot/humid weather. The key to do that is to pop my ears - I have to do that often, it's like I'm on a ...
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1answer
125 views

If water evaporates at below 100 degrees then why not stone?

I have asked this question recently: Why does evaporation take place? and I got a satisfactory answer, that temperature is macroscopic and is the average temperature of the object. That said, why ...
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2answers
40 views

Solar stills with Wine [closed]

Is it possible to obtain more concentrated alcohol by using wine in a solar still instead of seawater? If yes, as I suspected, how does the concentration (of alcohol) of the distillate vary with ...
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2answers
301 views

Why do liquids boil when their vapor pressure equals the ambient pressure?

Given that the boiling point of a liquid is the temperature at which the vapor pressure is equal to the ambient (surrounding) pressure, what significance does a liquid's vapor pressure have in the ...
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1answer
57 views

Is this air cooling idea feasible?

Massive heat wave here and I don't have an air conditioner. I was investigating how commercial air conditioners work and to my surprise found that they use merely evaporation rather than a ...
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2answers
134 views

Why do some hand dryers blow hot air?

I am not sure why some hand dryers are blowing hot air and not just air at room temperature. To me, hair dryers are just a way to dry one's hands using the same principle as when we shake our hands ...
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1answer
81 views

Salt water evaporation

Pardon my no-knowledge of the topic but I am curious about following characteristics of sea water evaporation: is it more efficient to have thinner ponds to which water is re-added or deeper ponds? ...
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1answer
95 views

Does stew lose more liquid if stirred as it cools?

Suppose I cook a stew or soup and then take it off of the stove and leave it uncovered to cool. Of course, it will cool faster if I stir it (more surface area), but it will, eventually, cool to room ...
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3answers
364 views

Why does water not evaporate in below 0 degrees?

I have learnt that, most objects still have energy in their atoms until the temperature reaches absolute zero. In other words, everything has energy around us. Now, that in mind if I go to antartica, ...
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2answers
522 views

Why does evaporation take place? [duplicate]

I was looking at at puddle when I thought that this puddle will evaporate tomorrow but then it occurred to me that the boiling temperature of water (aka to turn into gas) is $100$ degrees under 1 ...
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2answers
140 views

Reducing the evaporation of water at room temperature

Water drops kept on different surface evaporate after a few minutes. How can I reduce the rate of evaporation of these drops? Can I add some additives which suppress evaporation?
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2answers
93 views

Does the temperature of water determine how much heat will be removed from air used to evaporate it?

This is a question about evaporative cooling as used in residential evaporative cooling appliances. This type of cooling uses the heat in the ambient outside air to evaporate water and remove the heat ...
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2answers
1k views

Does Uchimizu (watering streets in summer) help reduce temperature in an area?

It appears that in Japan, there is an old custom called Uchimizu. The name is a combination of words "road" and "water". The essence of it is moisturizing small parts of populated areas like ...
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1answer
136 views

Can water evaporate when frozen?

If an ice cube is stored in a freezer could it evaporate given enough time? Is there a temperature below which water cannot evaporate (even just a little)?
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1answer
468 views

Why does a water drop on a hot plate at $150^o C$ evaporate faster than on a plate at $200^o C$?

I recently read that: "A drop of water landing on a hot plate at $150^o C \:(300 F)$ evaporates in a few seconds. A drop of water landing on a hot plate at $200^o C \:(400 F)$ survives a whole ...
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1answer
669 views

Behavior of water at temperatures above 100°C

Assuming you have container with heat insulation (something like boiler). You can store water at any temperature below 100°C. At these conditions, you can drill a hole into container and store water ...
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3answers
67 views

Vaporization in function of relative humidity

I am wondering how the relative humidity affects the vaporization? I saw on an other post that it doesn't affect it, but in my personal experience, it takes much more time to dry clothes when the ...
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3answers
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Does wrapping a wet paper towel around a glass bottle really speed up the cooling process?

There are claims like this one that you can improve the cooling speed of beverages when you put them wrapped in a wet paper towel inside the refrigerator/freezer. I've just tried it by myself and ...
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0answers
21 views

Time for which a drop stays in the leidenfrost point

Is there any way to find out the time required for a drop of given dimensions to vaporize after attaining Leidenfrost point?
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1answer
102 views

How does ice become thinner inside a no-frost fridge?

How does ice become thinner in a no-frost fridge? I thought ice can't evaporate at all since, well, it's below freezing temperature and it's solid, too. In my other yes-frost fridge, the ice never ...
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5answers
134 views

Ice cube on a scale

Lets put an ice cube on a fairly precise scale and take readings over a period of several hours. The ice cube is situated in a saucer so that the water is retained after melting. What will the ...
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9answers
13k views

How can water evaporate at room temperature? [duplicate]

Boiling point of water is 100 degree Celsius. The temperature at which water in liquid form is converted into gaseous form. Then how it possible for water to evaporate at room temperature?
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2answers
95 views

Why doesn't water start to boil in soils?

Consider the following two scenarios: I take a vessel filled with some water and evacuate the air, the water will (or rather can) start to boil; if the pressure in the vessel is << atmospheric ...
15
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1answer
857 views

Why doesn't breath condense around poop of flies on the window's glass?

One day it was raining outside and I was breathing on the glass of my window. I noticed that around the spots of fly poop there is a circle where vapor does not condense. With time the circle becomes ...
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2answers
237 views

Acer saccharum (Sugar Maple) Sap & Freezing

This may or may not be the appropriate scientific discipline to ask this question of, but I'll give it a shot. I'll happily invite chemists to chime in as well. It's time to tap sugar maples in the ...
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2answers
345 views

Auto-refrigeration

I'm reading about the auto-refrigeration effect and can't find a really good explanation. Is the idea that when you have your condensed liquid, and then release it into a low pressure environment, ...
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3answers
659 views

Does evaporation decrease entropy?

I have a container of water in thermal equilibrium (there are no temperature fluctuations inside the container). Some molecules will evaporate out of the container of water thus decreasing its ...
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2answers
99 views

The best way to cool the teapot

My professor today in the class made us a question: "Lets say we have a teapot with water in it.The water is hot.Now we want to cool the water. Will it cool faster if we put an ice cube above the ...
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4answers
335 views

Is vapour pressure based on partial pressures or just total pressure on the liquid?

The explanation for the boiling point of water is that at 100C, the vapour pressure becomes greater than atmospheric pressure. But say you had a a jar of water sealed in argon at 1atm, which is larger ...
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1answer
157 views

Psychorometric equation : calculation of dew point

I would like to calculate a dew-point temperature having wet and dry bulb temperatures and atmospheric pressure. I have the equation, but this equation uses following coefficients: A: 6.116441 K: ...
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1answer
313 views

How much does lighting of room effect evaporation?

Suppose there is a wet floor under normal conditions, how much can we alter the rate of evaporation of the wet floor by trying out different types of lights ex. Incandascnet, cfl, fluorescent etc ? I ...
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1answer
239 views

Does the temperature at which water evaporates influence the amount of chalk left behind?

I believe the title is straightforward. Evaporating water leaves behind chalk. Assuming you evaporate the same amount of (the same type of) water, does the temperature at which this happens (and so ...
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0answers
228 views

Does coffee with cream cool slower than black coffee?

At Modernist Cuisine, Nathan Myhrvold states that "Coffee with cream cools about 20% slower than black coffee". He then gives three reasons, two of them related to radiation and the third one to the ...
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2answers
145 views

How do you keep a fridge full of food cooler?

I just graduated and a mate moved into a flat (none of us are physicists by the way). So, were graduates, we got a new flat, and were broke. So, were now having a debate on how to keep a fridge ...
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2answers
130 views

Can you confirm 2 simple statements about vaporization?

Vaporization is an interesting engineering subject, but unfortunately much about it has always been unclear to me. Recent research of mine has brought my mind to link vapor pressure to boiling and ...
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1answer
429 views

Liquid nitrogen condensing oxygen out of the air

In this video, a pool of liquid nitrogen in a metal bowl can cool it enough so that oxygen from the air condenses at the bottom: ...
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2answers
503 views

Does coffee cool faster than tap water?

A friend of mine, based on casual observation, believes that coffee will cool faster than ordinary hot tap water. Being curious about this I have tried to investigate it myself, but I'm not well ...
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3answers
222 views

What limits the mass transfer from a boiler to a condenser in a sealed vessel?

If we set up an evacuated vessel where we keep one end at a higher temperature than the other, and then introduce a liquid at the warm end, it will evaporate and condense at the cooler end. If we trap ...
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0answers
226 views

Rate of evaporation of water

In our everyday life, does the temperature or humidity have a greater effect on how fast things dry? Are there any theories/models that explain this quantitatively?
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1answer
8k views

Thermodynamics: Are pressure and temperature enough to calculate enthalpy?

From the chart above, it looks like it is possible to calculate enthalpy from just pressure and temperature. After a few hours of Googling my question, I'm not able to find anything helpful. My ...
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2answers
526 views

Would a small puddle of water evaporate faster if you spread a dry towel over it?

Let's say you spill 10ml of water on the kitchen counter. It forms a small puddle that would evaporate after a while (assuming room temperature and sane humidity). Would spreading a large, dry towel ...